Why Interval Training Is King

It's a new decade and it is time we throw out old ways of doing things and bring in new more effective ways to reach our fitness goals. For 2010, I want you to take traditional moderate intensity, steady state cardio and toss it in a big Hefty trash bag. In this new decade, a decade of change and progress, you are going to shed fat without sacrificing muscle mass and cut the amount of time you do cardio by half or more! You are going to do so using some non-traditional methods of cardio, mainly by using interval training.

Burning calories and increasing the body's ability to perform longer bouts of aerobic exercise have long been the benchmarks for a successful workout regimen. Times are changing and bodies are changing. American's lifestyles have changed, science has progressed and we have a better grasp of the connection between fitness program design and physiological adaptations. We now know that it is not necessarily the total amount of time spent in the gym that is important, it is a high quantity and quality of work done in less time that creates the most drastic changes in a person's fitness levels. Instead of focusing on aerobic fitness, we now understand that focusing on the anaerobic (non-oxidative) energy system via weight training and interval training can elicit the greatest changes in body composition.

What makes interval training so special is its use of both the anaerobic and aerobic energy systems. By performing high intensity bouts of exercise followed by short rest periods the body is forced to rapidly recruit muscles and quickly fuel the activity being performed. This requires a series of extremely metabolically demanding processes that includes prompt carbohydrate metabolism and the release of growth hormone. After a few short bursts of high intensity activity, your body will have trouble uptaking enough oxygen to assist in fueling your exercise session, thus putting you in an "oxygen debt" as you continue to work out. Between the demand on your muscles and the oxygen debt, your body will continue to burn calories at an elevated level for several minutes or even hours as it tries to return to a normal resting state. This is known as EPOC or Excess Post-Exercise Oxygen Consumption. This physiological state is typically not reached with traditional steady state cardio using moderate intensities, especially in trained individuals who have already made some adaptations to their exercise program.

A study done by the National Institute of Fitnss and Sports led by Dr. Izumi Tabata tested the effects of steady state cardio and interval training on anaerobic and aerobic capacity over a six week period. The steady state group performed five days of moderate intensity cardio for thirty minutes each time, while the test group performed twenty second sprint to ten second rest intervals on a bike for a total of four minutes of work. The study found a 0% increase in anaerobic work capacity and a 10% increase in aerobic capacity in the steady state group. In the interval group, the study profoundly discovered a 28% increase in anaerobic capacity and a 14% increase in aerobic capacity! Just FOUR MINUTES of intervals trumped the thirty minutes of traditional cardio in terms of building an individual's fitness levels.

The studies are in and so are the results: intervals are much more beneficial for a person when it comes to building fitness and shedding body fat. It's time to suck it up, start working hard and save yourself some time and sanity by switching your cardiovascular program to a more  interval based routine. Obviously, if you are training for endurance based competitions, then you do not want to only perform intervals because your body specifically needs the function of endurance performance. With that being said, intervals should still be a part of even an endurance athlete's training program due to the fact that increasing one's anaerobic capacity and building a higher lactic threshold can increase endurance performance. Welcome to 2010 people, the year interval training took America by storm.